Cerium dioxide (CeO2) has a variety of applications. For example ceria nanoparticles are used in catalytic converters in the automotive industry to convert harmful carbon monoxide to less harmful carbon dioxide. The semi-conductor industry uses cerium dioxide nanoparticles as fine abrasive and polishing agent in the manufacturing of computer chips. Non-nanoscaled cerium dioxide can improve the light production/output in mantles of gas lanterns as the gas flame produces almost no light itself, whereas burning cerium oxide generates a yellowish-white colour.

How can I come into contact with this material?

Ceria nanoparticles may be present in the ambient air as the material is used as a catalyst/additive in some automotive fuels. However, there is no information available on this material with regards to the environment or on other sources that may release cerium dioxide nanoparticles. The chance of human exposure to ceria nanoparticles derived from applications such as gas lanterns or computer chips is very low since mantles in gas lanterns are rarely produced nowadays and they do not make use of cerium dioxide nanoparticles at all. Equally the production of computer chips during which ceria is uses as polishing agent takes place in highly isolated rooms.

Is there any risk from this material to humans and the environment?

Little information exists on the effects of cerium dioxide nanoparticles on humans or the environment. Literature sources show that there could be positive and negative effects. There is no danger associated with small amounts of cerium dioxide. Currently it is also assumed that very little nano-scaled cerium dioxide exists in the environment.

Conclusion

Future studies need to be performed to conclusively determine the effects of cerium dioxide nanoparticles on humans and on the environment. Currently various international research projects are focused on investigating the effects, including the long-term effects, of cerium dioxide nanoparticles.

By the way...

Cerium, as cerium oxide, is a rare metal and was named after the dwarf planet Ceres that is located in the asteroid belt between Mars and Jupiter. It is not clear if either cerium or cerium dioxide is present on Ceres. The NASA probe Dawn, who arrived at Ceres in February 2015, could not clarify this: cerium was simply not on the agenda for this research program.